McAfee slaps Trojan warning on MS Office Live

McAfee has apologised after an anti-virus update released on Monday night incorrectly identified a plug-in for Microsoft Office Live Meeting as a Trojan.

The signature update file mistakingly flagged LMCAPI.exe (a component of Live Update) as a Trojan called Swizzor. As a result the component was incorrectly deleted from thousands of desktops at one huge multinational, staffers from which informed us of the problem but requested anonymity. Techies at the firm had to roll out new versions of Live Update as well as an updated signature file that avoids the false alert.

In a statement, McAfee said the snafu affected only a "small percentage" of its enterprise customers.

The issue was rapidly identified and corrected in the signature release on Tuesday 5th August, with any customer contacting McAfee prior to the release of the corrected signature being given an additional DAT file that suppressed this incorrect identification.

McAfee Avert Labs aims to maintain a high-level of proactiveness and accuracy in its generic detection signatures and to minimise false positives, while making any required corrections as rapidly as possible. McAfee would like to apologise to any customers affected by this issue.

Faulty anti-virus signature updates are a generic problem faced by all security vendors from time to time. Previous examples have included a Kaspersky update quarantining Windows Explorer, AVG crying wolf at Adobe Reader and, more recently, both CA and McAfee decided that legitimate JavaScript apps were malign.

These are three examples of a problem we've written about many times in the past and for which no ready solution is apparent. Effects vary by environment and miss-diagnosed application but can run to anything from the automatic deletion of a component no-one misses to locked-up workstations in the worst cases, which are mercifully rare. ®